David Cameron's appointment of strategist Lynton Crosby signals a shift towards appealing to core voters and the 'politics of old', according to political comms agency people.

It emerged over the weekend that Crosby has been called in by the Conservatives after he handled a successful campaign to get Boris Johnson re-elected as mayor of London.

However, news of his appointment comes after a warning against the move by Tory donor Lord Ashcroft, amid reports he may prove divisive within the party.

MD at Bell Pottinger Public Affairs Stephen Lotinga pointed to Crosby’s campaigns before his work with Johnson, which included the masterminding of successive election victories for Australian Prime Minister John Howard.

Lotinga said: ‘I think they’re either trying to appease the right of their party or they’re going to genuinely run a campaign that is shifting back to a more Tory focus, and especially that of the core of the right wing vote - that’s what he specialises in.’

He added that the appointment was likely to result in campaigns that divided the electorate, ‘focusing on the issues the Tories can win rather than trying to appeal to all bases.’

This, he said, would likely lead to a pre-coalition ‘politics of old’, with the Tories vulnerable to attacks as ‘the nasty party’ by Labour and Liberal Democrats.

Last month, former deputy party chairman Lord Ashcroft said bringing in Crosby would be a mistake and a recipe for 'conflict and confusion'.

INHouse Communications’ Jo Tanner worked with Crosby on Johnson’s campaign in 2008 and called him ‘confident and clever,’ as well as a keen poller 'who follows what the numbers say'.

Pointing to the departure of figures such as Andy Coulson from Number 10’s strategy line-up, she said he could bring vital experience and a more politicised focus on campaigning.

'He has a stronger Tory view and he has a good track record in mobilising that core vote,’ she added.